Is it a miscaridge or just spotting?!!

Hi I'm currently around 5-6weeks pregnant. This will be my 3rd child in 3years. I started bleeding with pains yesterday am. Went to the doctors yesterday and had a scan they said there was no visible pregnancy but my pregnancy test at the hospital came back possitive. They ran bloods & I have to go back in 2days for more bloods. I was just wondering what the chance are that this wasn't a miscaridge?